There is a group of children whose only apparent developmental delay occurs in the domain of language. These children characteristically display severe limitations in their lexical development. The proposed research is a pilot investigation of lexical productivity among language-impaired children. Specifically, this study focuses on the productivity of the causative alternation among English-speaking specifically language-impaired (ESLI children, comparison groups of English-speaking normally developing children (END), and normally-developing K'iche'-speaking children (KND). Despite their documented difficulties with lexical acquisition, relatively little is known concerning how ESLI children incorporate syntactic restrictions in their knowledge of lexical entries. The causative alternation is especially interesting in relation to lexical acquisition. There is evidence that normally developing children experience some difficulty in acquiring the causative alternation. They might say 'I steepened its walls' (= I made its walls steeper). One hypothesis is that children learning English come to rely upon a restricted set of semantic features to distinguish between verbs that undergo the causative alternation and those that do not. The semantic features break the verb lexicon into distinct subclasses such that some subclasses (change of state or contained motion verbs) allow the causative alternation while others (verbs of volitional action or motion in a specified direction) do not. ESLI children may find it difficult to learn the causative alternation for at least three reasons. First, ESLI children may find it especially difficult to extract information about the linguistic context of words. Second, while having some ability to learn new words, ESLI children may not be able to extract generalizations from their learned vocabulary as easily as normally developing children, Third, once ESLI children had acquired a new word, they might experience unusual difficulties in retrieving that specific word in the course of a conversational exchange. This pilot study represents the first attempt to elicit causative errors from ESLI children. The value of this preliminary research is twofold. First, it allows for a rudimentary evaluation of ESLI children's use of verbs in varying linguistic contexts as revealed by the causative alternation. This information may contribute to understanding the nature of specific language impairment. Second, it allows for testing the underlying assumptions associated with the theoretical positions that concern the organization of the verb lexicon by using crosslinguistic comparisons.